An energy management system (EMS) is a system of computer implemented tools used by operators of electric utility grids to monitor, control, and optimize the performance of the generation and/or transmission of an energy delivery system. In other words, an EMS optimizes, supervises and controls the transmission grid and generation assets. The monitoring and control functions are known as “supervisory control and data acquisition” (SCADA). Primary frequency control involves autonomous automatic actions by the EMS to arrest deviations in power system frequency whenever imbalances arise between load and generation. Primary frequency control actions are fast; They are measured in megawatt (MW)/seconds. Primary frequency control actions include governor response, load, damping, and voluntary frequency-responsive load control, all of which contribute to frequency response. Secondary frequency control involves centrally coordinated actions by the EMS to return frequency to its scheduled value. Secondary frequency control actions are slower than primary frequency control actions; they are measured in MW/min. They are deployed both during normal operations and after primary frequency control resources have arrested frequency following major disturbances. Secondary frequency control actions include generation (or load) that responds to automatic generation control (AGC) signals or to operator dispatch commands. AGC is often referred to as “regulation” service.
Area Control Error (ACE) is the difference between scheduled and actual electrical generation within a control area on the power grid, taking frequency bias into account. To elaborate, generating an amount of electricity in exact equilibrium with consumption (load), is extremely difficult and also quite impractical. Instead, generation controllers strive to continually alternate between over- and under-generating. For instance, in a particular control area, the generation dispatcher's official target might be to cross the break-even point (i.e., a zero ACE value) fifteen times per hour.
The formula for calculation of ACE is as follows:ACE=(NIA−NIS)−10b(FA−FS)Tob+IME Where,                NIA represents actual net interchange (MWs)        NIS represents scheduled net interchange (MWs)        b represents the control area's frequency bias setting (MW/0.1 Hz)        FA represents actual system frequency (Hz)        FS represents scheduled system frequency (60.0 Hz in America)        Tob represents scheduled interchange energy used to bilaterally correct inadvertent, accumulations (MWs)        IME represents a manually entered amount to compensate for known equipment error (MWs)        
For a typical energy management system (EMS), the main objectives of Automatic Generation Control (AGC) are to regulate the active power output of generating units; maintain the desired net interchange; maintain interconnected system frequency; dispatch generating units in an optimal manner to minimize production cost; monitor and maintain sufficient available system reserves to meet system reserve requirements. A common problem/concern is the excessive unit movements during generation control and dispatch to maintain power balance and regulate frequency close to a desired frequency level (e.g., nominal frequency). Therefore, what is needed are systems, methods and apparatus for improved regulation of such energy delivery systems.